Apparatus for charging storage batteries.



A. S. KROTZ.

APPARATUS FOR GHARGING STORAGE BATTERIES.

APPLICATION FILED IAN-12, 1905.

Patented Sept. 6, 1910.

3 SHEETS-SHEET 1.

Wit" mam A. S. KROTZ.

- APPARATUS FOR CHARGING STORAGE BAT'I'IIBIES.

APPLIOATIOI PILBD L12, 19 05.

Patented Sept 6; 1910.

3 SHEETS-SHEET 2.

A. s. KRQTZ. APPARATUS FOR CHARGING STORAGE BATTERIES.

APPLICATION FILED J'AI.12, 1905. I

Patented Sept. 6, 1910.

3 SHEETS-SHEET 3.

M IIIHIIIIIIIIIHIlllllllil UNITED STATES PATENT OFFICE.

ALVARO S. KROTZ, 0F SPRINGFIELD, OHIO, ASSIGNOR 0F ONE-HALF TO PAUL A.STALEY, OF SPRINGFIELD, OHIO.

Specification of Letters Patent.

Patented Sept. 6, 1910.

Application filed January 12, 1905. Serial No. 240,720.

apparatus for charging storage batteries,

particularly that class of batteries which need frequent chargin and areused by unskilful operators suc as automobile batteries and batteriesused for similar purposes.

The object of my invention is to provide means by which a battery ofthis character can be properly charged without any attention on the partof the operator other than the proper setting of the apparatus and the,

operation of a switch for turning on the current, the apparatus beingsuch that the battery will be charged in the most efficient manner andautomatically disconnected when properly charged.

It has been found by experience that storage batteries, particularlythose used in automobiles, receive more in'uries and sustain a greaterloss in their e ciency from improper charging than from discharging. Inorder that a battery of this character shall have the highest efficiencyit is desirable that it receive an initial charge at a comparativelyhigh rate until it has attained a suiticient voltage, after which therate of charge shall be reduced until fully charged. It is desirablealso that at certain periods the battery should receive an overcharge ata low rate for a definite length of time, de-

pending upon the use and condition of the battery.

I accomplish all these objects by the methods and apparatus hereindescribed in such a way that the results will be attained with certaintywithout the requisite of any technical knowledge or skill on the part ofthe operator.

The invention consists in the apparatus hereinafter described and setforth in the claims.

In the accompanying drawings, Figure 1 is a diagrammatic viewillustrating a method and apparatus embodying my invention. Fig.2 is asimilar view showing a modification. Figs. 3 and 4 are detail views ofthe apparatus shown in Fig. 2. Fig. 5 is a diagrammatic view showing afurther modification.

Like parts are represented in the several views by similar characters ofreference.

In carrying out my invention I employ an automatic cut-out device ofnovel construction in connection with circuits and other apparatus bymeans of Which the method of charging to secure the best results arecarried out. Various forms of this cut-out device may be employed, butin order to carry out the method of charging in its most successfulapplication to the work to be performed tlns cut-outdevice is employedwith two opposing ma nets, one of which is lo cated in a shunt o thebattery to be charged and the other connected to a source of electricsupply of constant potential, such, for instance, as the main line.

In the accompanying drawings, a a rep resent the storage battery to becharged.

a and a represent the main lines from which the current is to besupplied. To

secure the best results in carrying out this method the main chargingcircuit is provided with three branches, each of which contains acircuit breakin device and each so arranged as to have a differentamperage. The first of these circuits or branches has the largestamperage, the second a less, and the third preferably a slightly reducedaniperage. Each of the lines may be provided with variable resistancesto vary their amperage, though as a rule these resistances may be fixedwhen the same batteries or batteries having like potentials andcapacities are to be charged. The first and second of these circuits orbranches are so constructed that the circuit breakers therein will becontrolled by the potentials of the battery and the third by a timingapparatus which shall be independent of the potential of the battery.

Referring to Fig. 1, it will be seen that each of the three circuits orbranches named are adapted to be controlled by a single automaticcircuit breaking device, I). A circuit breaking arm, 0, preferablyspring actuated, is adapted to break the circuit under certainconditions from the respective termmals, 0 c and 0 in the severalcharging circuits or branches. The circuit breaking arm, 0, is connecteddirectly to one pole of .the battery, the other pole being connected tothe main line as shown. If more than one circuit breaker is used theywill be connected,

in series to one pole of the battery. The other pole of the main line isconnected to the respective'circuits, d, d and (i each of said circuitsbeing preferably provided with resistance, 6, e and 6 to give to thesaid circuits the desired amperage. The arm, 0, of the circuit breaker,b, is held in position by a catch, 0 which is adaptedto be disengaged bya movable core, 6 passing throughthe magnets, 12 6 These magnets, b b,are connected respectively to a shunt of the battery, 11. a, and to asource of constant potential or the main line. These .magnets may bewound together at opposite ends of the core, or they may be employedseparately and the core made in two parts. In either event the movablecore is capable of adjustment so that the opposing pull of the magnetscan be properly disposed on the core to cause it to move at thepropertime. This may be accomplished by screwthreading the part whichnormally supports the movable core, as shown in Fig. 5. The magnet, 6being connected to the main line, or some other source of constantpotential, has a constant pull, except as influenced by temperature, ashereinafter described, while the magnet, 6 being in the battery shunt,has a varying pull depending upon the potential of the battery. Y 1

Referring now to Fig. 1, I have shown the circuit breaking device, I),with the magnets or coils, b and 12*, arranged one above theother; themovable core, 6 therein being adapted to move'vertically and to drop byavity when uninfiuenced by the magnetic pull of the coils, b and b thecore having an extension, 6*, adapted whendrawn upwardlyto cont-act withthe end of the catch, 0*. The arm, 0, is provided with three notches, 0,a and 0 each adapted to be engaged by the catch, a, and when so engagedto hold said arm in contact with one of the terminals, 0 c c ,'ot thebranch circuits, d d d this circuit breaking arm, c, being connected tothe battery through a line, d.

In this simple form of the apparatus ad? vantage is taken of the factthat in ordinary storage batteries the potential of the batteryincharging is correspondingly her under a higher rate of charge than inow rate of charge. IIence, in starting discharge the arm, 0, is laced incontact with the terminal, 0 which will give the highest rate of charge.When the battery has at this rate of charge reached a certain givenpotential or voltage the increased pull on'the magnet 6 resulting fromthis voltage will cause the core to be drawn up-- wardly, contact withthe catch,c withdraw it from the notch, 0 of the arm, a, and permit saidarm't-o be drawn out of contact with the terminal d j This breaks thechar circuit. The voltage on the line, (i wi be reduced and the magneticpull of the coil, 2),

reduced, while the coil, 6 will be constant and will cause the core tobe drawn down and allow the catch to engage in the second notch, c, withthe circuit breaking arm, c, in contact with the second terminal, 0 ofthe branch, (Z thus securing a still lower rate of charge and acorrespondingly lower battery voltage. This rate of charge willgenerally be arranged so that, the battery being in normal condition,the proper voltage to again operate the core will be that of the batterywhen it is fully charged. This will a ain cause the core, 6 to beoperated and a low the arm to move to the next terminal, 0 or the lowestrate of charge. This low rate of charge will not ordinarily, under thenormal condltions of the battery, aflI'ect the voltage or potentialthereof, but will be in the nature of an over charge, and inasmuch asthe voltage will not be increased thereby, means are provided by which,after a certain definite length of time during which it is desired toover charge the battery, the third and last charging circuit will bedisconnected. In Fig. l I have shown this accomplished through the aidof a timing device which is adapted, after a certain length of time, to

break the circuit from the main line through the constant magnetic coil,6 This maybe done in various ways, but I have shown a simple clockwork,f, having a detent, f adapted to: be engaged by an extended portion, oof the arm, 0, while the arm, 0, is passingfrom the terminal 0 of theterminal, 0 The catch, a, will engage in the .notch, 0 of the arm andhold it on the terminal 0 At the same time the clockwork, f, having beenset in motion, will, after a certain definite time, break the circuit tothe coil, b and thus relieving'the magnetic pull of this magnet, willproduce another movement of the core, 72 which will finally disconnectthe arm, c, and entirely disconnect the charging circuit. To provide forvarying the length of time during which this this purpose... The timingdevice being set in motion just prior to the time that the contact ismade for the last charging circuit, this last or over charge willcontinue for a length of time depending upon the position of thecontacting part f. A stop, f, is preferably employed for the circuitbreaking arm, f so that when the circuit is broken.

the timing device will be arrested," it being ";views of the circuitbreaking arm, c, the

hehl by the contacting in, f, against the arm, f, which in turn 1srought against the stationary stop, f. In order to prevent the arm, 0,from moving past either of the said terminals it maybe provided with adash pot, c, or other suitable means to prevent a too rapid movementthereof.

In Fig. 2 I have shown a slight modification. The coils, b and V, areshown separate and the core, I), is made in two parts, thelower part,I), being normally stationary but screwthreaded as shown in Fig. 5, soas'to be adjustable to securethe proper movement of the upper part, b.The magnetic pull of the constant coil, 6 will operate on the movablecore, I)", through the core, 6 I have also shown in this figure theupper coil, 6 provided with two terminals which connect to the batterythrough the means of circuits, g and g one ot these terminals beingconnected to the core winding so that less magnetic influence will beproduced than through the other. Contacting points q g, are provided tocontact with the arm, a, so that the second movement of the arm, 0, maybe secured at a higher or lower voltage as desired, by reason of thegreater or less 'magneticinfluence produced in the coil, 5 through thedifi'erent circuits, 9 and 9 These contacting points, 9 and g, in.connection with the arm, 0, form a circuit breaker for the magnet, 6which, as the arm 0 moves, will completely cut out said magnettemporarily and thus rob it of its magnetic influence and cause the coreto be moved quickly to its normal position and permitting the catch, 0*,to return to its working position during the movement of the arm, 0,from one contacting point to another. I have also shown a modificationin the third or overcharge circuit. In this case the mechanical timingdevice is dispensed withand after the second movement of the arm, (2,the current is directed through terminals, h h in a vessel containing aconducting liquid such as water, which will be evaporated by the heatproduced in the passage of the current through the same. One of theterminals, l1, will be immersed in the water a suiticient distance sothat after a certain amount of evaporation has taken place the liquidwill pass'below the end of said terminal, thus automatically breakingthe circuit.

Ihave shown in Figs. 3 and 4 detail rm being provided with a snapswitch, t. adapted, as the arm leaves the terminal,

"toib'reak thecircuit: In setting the device, that is, moving the'armfrom left toright,

- the snap switch'will be held out of contact by the operator,preferably by placing his thumb on the end of the switch over thespring.

In Fig. 5 a still further modification is shown where I have shown twoseparate circuit breakers having separate arms, each capable of a singlemovement. This arrangement may be employed when the first charging rateis to be continued to a voltage less than the normal voltage of thebattery when full. For instance, assume that the first charge should beat the rate of amperes until the battery reached a voltage of or 62,when the. second charge at the rate of 15 amperes continues until thebattery reaches a voltage of 64.

Asis well known under favorable conditions the circuit breaking deviceswill operate with a single coil placed in the shunt of the battery, thepotential of the battery alone being adapted to operate the core, I), todisconnect the circuit breaking arm. Inasmuch, however, as theresistance of the coil is afiected by the temperature, it has been foundby experience that such a device is unsatisfactory where used in varyingtemperature, the circuit breaker operating sooner or at a lower voltagewhen the coil is cold than when it is warm. By using two coils ofsubstantially the same resistance the variation in resistance caused byheating will be compensated for and one balance the other.

By the operation herein described and the apparatus set forth I amenabled to charge a battery under the most advantageous circumstancesand in a manner by which injury is impossible and its highestefli'ciency-maintained. It is only necessary for the operator toproperly set the device and start the current by any suitablecontrolling switch (not here shown), the remainder of the method andapparatus being wholly automatic in its nature.

By employing two coils in the circuit breaking device, one acounteracting .coil connected so as to have a fixed potential, bothcoils will increase or decrease the magnetic influence alike inproportion to the temperature of the coils or other changes which willact upon both coils alike, and

.the effective force which starls the operation of the device is adifferential one determined by the differences in the voltage as thebattery is more or less completely charged. These opposing coils beingotherwise subjected to the same influences in substantially the sameway, the device will be operated whenever the battery voltage reaches acertain voltage regardless of the temperature of the coils or otherinfluences which affectbothcoils alike. It will be understood, ofcourse, that as soon as the core starts to move it moves out of themagnetic influence of the constant coil and rapidly into that of thevariable coil, so that as soon as the pull of the constant coil has beenovercome the movement will be a rapid one to produce the operation ofthe circuit breakers.

As arranged in Fig. 1, the point at which the cutout device will operateto change the charging rate may be fixed; that is, the voltage requiredto operate the device from a higher to a lower rate of charge will bethesame as that for the succeedin operations a predetermined voltage inthis case being adapted to successively operatev the device for eachrate of charge, this being accomplished, as before set forth, by thefact that until the battery has reached its normal casay 60. It wouldcontinue at this rate until 64 was again reached, when it would beopcrated again. At this low rate of charge the battery ought to receiveits full charge by the time the voltage has'again reached 64, when thedevice will again be operated and completely out off the circuit exceptfor the overcharging device. It is obvious that any reasonable number ofsteps may be used by this means depending on the rates desired forcharging. For instance, if the highest rate were say amperes, a secondrate of 30 amperes and a third or final rate of 15 amperes might beobtained, using the same voltage to successively operate the cut-outdevice; these difi'erent changes in the char ing rate being sutlicientto cause a variation 0 the voltage in the battery shunt tosuccessivelyoperate the device as described.

When two separate devices are used as shown in Fig. 5, in case the firstone should fail to operate, the operation of-the second one will breakthe charging circuit and cause the current to pass through theover- Icharging device.

In Fig. 1 I have shown the variable coil connected permanently in thebattery circuit. It is obvious that this connection can be made the sameas shown in Fig. 2 so as to be open while the arm 0 is passing between,contacts; thus cutting out the coil, b

causing the 'core to more quickly operate,

and insuring the operation of the coil. It isobvious that the rise inthe potential of the-battery in chargingwill slightly vary the amount ofthe charging current which ever rateis being used, hence it is notintended to imply that the charging rate is exactly constant at thedifferent rates iven,

' yet this variation by reason of the rise in the potential of thebattery is small in comparison with the change which I make from thehigh to the low by using the diiierent circuits having differentresistance.

Having thus described my invention, I claim 1. In combination with asource of electric supply and a battery to be charged, a connectionbetween said battery and said source of electric supply adapted tonormally charge said battery at a maximum rate, and means controlled bythe potential of said battery to vary the "electrical connection toproduce a lower rate of charge when a predetermined voltage in thebattery has been reached, substantially as specified.

2. In an apparatus for charging storage batteries, means controlled bthe accumulated voltage of the battery in chargingto successivelyreducethe charging rate and to automatically bring into operation atiming device to give the battery a definite overcharge when it hasreached its normal charged potential,'substantially as specified.

3. In an apparatus for charging storage batteries, means controlled bythe variation of the potential of the battery in charging tosuccessively change the rate of charging and to automaticallydiscontinue the charging when the battery has reached its normal chargedpotential, substantially as specified.

4. .In acharging apparatus an automatic circuit breaker having twoopposing magnets and a movable core, said magnets being arrangedsuccessively and longitudinally along said movable core in the directionof its travel, one of said magnets being arranged in a circuit ofconstant potential and the other magnet being in a circuit of varyingpotential, means for adjusting the normal position of said core so as tovary the operative difi'erential pull of said magnets.

5. In an automatic circuit breaker for a charging apparatus, opposingmagnets operating on a movable core, said magnets being arrangedsuccessively and longitudinally along said core in the direction of itstravel, one of said magnets being located in a shunt of the chargingcircuit and the other in a circuit having a constant potential,substantially as specified. I r

6. In a circuit breaker for an apparatus, two opposing magnets operatingupon a movable core, one of said magnets being in a shunt of the devicebeing charged and the other in a' circuit of constant potential, andmeans for varying the differential magnetic pull of themagnets of saidcore, substantially as specified.

7. In a circuit breaker for charging apparatus, a magnet arranged in ashunt of the device being charged, a circuit breaker arm having a seriesof steps and a series of contacting devices. representing chargingcircuits of ditl'erent amperage, a catch for said arm, and a movablecore in said magnet adapted, when operated, to contact said catch torelease said arm whereby the circuit breaker is adapted to besuccessively operated, substantially as specified.

8. In a charging apparatusaplurality of circuit breaking devices, andmeans to operate the same to change the char in'g rate from a hi her tolower am erage Jy variation of t e volta e in t e device being charged,a timing evice and means for set-' ting the same into operation when thedevice being charged has reached its normal potential, substantially asspecified.

9. In a charging apparatus, an automatic circuit breaker having twoopposing magnets, one in the shunt of the device being charged and theother in the mainline, a circuit breaking arm adapted to be operated bythe differential magnetic pull of said magnets, a'timing device adaptedto be set in operation by said arm, and a circuit breaker for the mainline magnet operated byathe timing device, substantially as specine 10.In a charging apparatus a circuit breaking device adapted, whenoperated, to change the charging rate from a higher to lower. amperage,a ma etic coil having a movable core, said core eing adapted under theinfluence of said magnet to release said circuit breaking device andcause it to be moved to a different position, and means for temporarilybreaking the circuit to said magnet While said circuit breaking deviceis moving from one connection to another.

' 11. In a charging a paratus a circuit. breaking device adapte whenoperated to change the charging rate from a higher to lower amperage, anelectro magnet having a movable core adapted when operated to releasesaid circuit breaking device and means connected with said circuitbreaking vdevice to break the circuit to said magnetwhile said circuitbreaking device is moving from one connection to another, and a timingdevice also adapted to be set in operation by the final movementof saidcircuit breaking device to give an additional electric charge for apredetermined length of time as specified.

12. In combination with a source of electric supply and a battery to becharged, connection between said battery and said source of electricsupply adapted to normally charge.

batteries, and in connectionwith a source of electric supply, anelectrical connection adapted to carry an initial charge at a high rate,and means controlled by the potential of the battery while charging tochange said connection to secure a charge at a lower rate, a timingdevice, and means controlled by the normal potential of said battery tocause said timing device to be set into operation to give the battery adefinite overcharge, substantially as set forth.

In testimony whereof, I have hereunto set my hand this 4th day ofJanuary A. D.

ALVARO S. KRO'RZ- Witnesses:

Crma- I. WELoH, F. LLEWELLYN WALKER.

